Automatic pneumatic lock



H. PIERCE.

AUTOMATIC PNEUMATIC LOCK.

APPLICATION HLED JAN- 5, 1918.

1,397,933. Patented Nov. 22, 1921.

Harry Pierce.

frrg. 3.

1 s2 moi/ QSM UNITED STATES PATENT OFFICE.

HARRY PIERCE, OF OAKLAND, CALIFORNIA, ASSIGNOR OF ONE-HALF T0 FRANK A. BRIGGS, 0F OAKLAND, CALIFORNIA.

AUTOMATIC PNEUMATIC LOCK.

Specification of Letters Patent.

Patented Nov. 22, 1921.

Application filed January 5, 1918. Serial No. 210,489.

To all whom it may concern:

Be it known that I, HARRY Prnnon, citizen of the United States, residing at Oakland, in the county of Alameda and State of California, have invented certain new and useful Improvements in Automatic Pneumatic Locks, of which the followin is a specification.

This invention is an automatic pneumatic lock for looking .a pneumatic.

This invention embodies part of the structure of my player piano record centering mechanism disclosed in my application Serial No. 210,490 filed Marchlzi, 1918.

The invention is illustrated in the accompanying drawing which forms a part of this specification andthe appended claims.

Referring to the drawing,

Figure l is a side view of a pneumatic embodying my invention.

Fig. 2 is a sectional view of said pneumatic taken on the line 2-2 of Fig. 1.

Fig. 3 is a sectional view of the pneumati and lock pneumatic exhaust tubes.

In the dra ring, 1 indicates a pneumatic which includes a side wall 2. An exhaust tube 3 communicates through a small vent 3* in the end or" said tube with said pneumatic, which tube is connected to a vacuum pump A. The wall 2 is provided with a recess 4. A lock pneumatic 5 is mounted in the wall 2 within the recess l and communicates with the exhaust tube 3 through tube 6. A pawl 7 cc red to the movable member of the lock pneumatic 5 extends through a slot 8 in the wall 9. for engagement with a ratchet l0 pivoted to the pneumatic wall 11 opposite the wall 2. The ratchet is provided with a longitudinal slot through which extends a pin 1 for maintaining'the ratchet in position for engagement with the pawl .7. An air tube 15 communicates with the pneumatic l which tube is controlled by a valve B. A spring 16 is interposed between the lower wall of the recess 4 and the movable member of pneumatic 5 for expanding the pneumatic.

When the exhaust pump is operated the lock pneumatic 5 is exhausted, the pawl 7 is disengaged from the ratchet 10, and the pneumatic l is unlocked, allowing the pneumatic to open and close. When the exhaust pump stops the loclc pneumatic 5 expands under the influence of spring 16, and pawl 7 engages ratchet 10 and locks the pneumatic 1.

Having described my invention, I claim as new and desire to secure by Letters Patent:

1. In a device of the character as disclosed, a pneumatic, an exhaust tube communicating with said pneumatic, an air tube connected to said pneumatic, a lock pneumatic connected with said exhaust tube, a pawl actuated by said lock pneumatic, a ratchet connected to and movable with said pneumatic, said pawl being adapted to engage said ratchet and'lock said pneumatic when the lock pneumatic is expanded.

2. In a device of the character disclosed, a pneumatic, an exhaust tube communicating with said pneumatic, an air tube connected to said pneumatic, a lock pneumatic connected to said exhaust tube, a ratchet pivotally connected to the movable member of said pneumatic and provided with a longitudinal slot, a pin on the stationary member of said pneumatic projecting through said slot, and a pawl actuated by said lock pneumatic for engaging said ratchet and locking said pneumatic when the vacuum in the lock pneumatic is destroyed.-

3. In a device of the character as disclosed, a pneumatic, an exhaust tube communicating with said pneumatic, said pneumatic being provided with a recess in its stationary member, a lock pneumatic mounted in said recess and connected to said exhaust, a spring for expanding said lock pneumatic when exhausted, a ratchet pivotally connected to the movable member of said pneumatic and provided with a longitudinal slot, a pin on the stationary member of said pneumatic projecting through said slot, and a pawl on the movable member 01' said lock pneumatic for engaging said ratchet and locking said pneumatic when the vacuum in the lock pneumatic is destroyed.

In testimony whereof I afiix my signature.

HARRY PIERCE. 

